Liquid Crystals - Beyond Color Generation
Liquid crystals, common in electronic displays, have been found to exhibit remarkable properties beyond color generation. Research by the Osuji lab at the University of Pennsylvania revealed that under specific conditions, these molecules form complex networked structures of filaments and flattened discs, capable of transporting materials similar to biological systems. Phase separating liquids typically form spherical droplets, driven by surface minimization. This work demonstrates that the alignment of liquid crystals within these droplets can deform fluid interfaces, driving the formation of more complex architectures and emergent active dynamics. This discovery, published in PNAS, may lead to self-assembling materials and new cellular activity models.
news releaseMachine Learning without a Processor
The capabilities of digital artificial neural networks grow rapidly with their size. Unfortunately, so do the time and energy required to train them. By contrast, brains function rapidly and power-efficiently at scale because their analog constituent parts (neurons) update their connections without knowing what all the other neurons are doing; in other words, they update using local rules. Recently introduced analog electronic contrastive local learning networks (CLLNs) share this important property. However, unlike brains and artificial neural networks, their capabilities were limited and could not grow with size because they are linear. Here, we experimentally demonstrate that nonlinearity enhances machine-learning capabilities in an analog CLLN, establishing a paradigm for scalable learning systems.
read articleMark Licurse Honored for Teaching Excellence
Mark Licurse, the LRSM Director of Education & Outreach, has been awarded the prestigious Hatfield Award for Excellence in Teaching in the Lecturer and Practice Professor Track. The award recognizes Licurse’s outstanding ability to effectively communicate complex concepts, innovate in undergraduate instruction, and inspire students to excel in engineering and science.
An alumnus himself, Licurse earned his B.S.E and Ph.D. in Materials Science and Engineering from Penn in 2006 and 2013, respectively. The Hatfield Award further cements his role as an exceptional educator.
news releaseSam Dillavou wins Postdoctoral Speaker Award
The annual Postdoctoral Speaker Award sponsored by the American Physical Society’s Topical Group on Statistical and Nonlinear Physics (GSNP) was won by Sam Dillavou, for his talk on “The Ensemble Peels the Onion: Emergent Learning Via Sequential Error Mode Reduction.” Sam’s work is part of IRG1 on Learning Metamaterials, in the lab of Doug Durian in collaboration with Andrea Liu and Mark Miskin.
read articleAshley Wallace, 2024 Models of Excellence Recipient
DEEPenn STEM 2023 Helping to Provide a “Roadmap” to be Successful in Graduate School
Dr. Ashley Wallace, the LRSM Associate Director of Diversity & Student Engagement, coordinated the second iteration of Diversity Equity Engagement at Penn in STEM (DEEPenn STEM) weekend that took place in person October 6-8, 2023. Aiming to diversify graduate-level programs and the global workforce through methodical recruitment and retention efforts, DEEPenn STEM was created specifically for those with limited access to resources and guidance for pursuing advanced degrees in the STEM fields. It was designed to serve as an integral part of the STEM pathway for students to pursue summer research experiences (ex: REUs) at Penn and successfully transition into graduate school and/or STEM careers. Not only showcasing the interdisciplinary nature of STEM-related graduate research at Penn, the event also addressed the unspoken rules and questions for prospective graduate students, providing participants with a “roadmap” to be successful in graduate school and related endeavors. Following a highly successful inaugural program in 2022, the program saw significant growth in expanding to 5 schools (Schools of Arts & Sciences, Engineering & Applied Science, Medicine, Nursing, and Veterinary Medicine), showcasing an even greater variety of pathways in STEM that Penn has to offer. Sixty-nine (69) undergraduate students from universities and colleges across the USA participated in the 3-day program. Key highlights include: keynote address delivered by Penn’s esteemed Provost Dr. John L. Jackson, dessert reception hosted by Dr. Valarie Swain-Cade McCoullum (Vice Provost for Student Engagement), remarks by Deans of each school, faculty research talks, instructional workshops, panel discussions, poster presentations, and a number of opportunities to network with current Penn faculty, staff, graduate students, and postdoctoral fellows. The LRSM co-sponsored the event and supported the attendance of 5 students from our Partnership for Research and Education in Materials, with the University of Puerto Rico.
web pageThe LRSM Receives $18 Million Renewal Grant
The Laboratory for Research on the Structure of Matter (LRSM) has secured an $18 million renewal grant from the National Science Foundation (NSF). The LRSM has been funded by the NSF for half a century, with the laboratory’s distinguished status as an NSF-Materials Research Science and Engineering Center (MRSEC) since its establishment in 1994. The generous infusion of $18 million is poised to fortify LRSM’s ongoing mission of conducting groundbreaking interdisciplinary research and fostering innovation. With this support, LRSM is well-positioned to drive forward its two new Interdisciplinary Research Groups (IRGs), focusing on the development of innovative materials capable of adapting to their surroundings and external stimuli, as well as the creation of tissue-like synthetic biomaterials constructed from cellular building blocks. These initiatives promise to open new frontiers in materials science, further solidifying LRSM’s standing as a beacon of pioneering research in the field.
read moreIn Memoriam: Gilbert J. Sloan, Ph.D., 1928-2023
We are sorry to report the passing of Dr. Gilbert J. Sloan on May 25, 2023. He was 94 years old and still a volunteer in the LRSM for ~15 years. Gil retired from DuPont in 1994, having started with the company in the Central Research Department in 1953, after a successful career, first as a senior research scientist and later as Manager of Analytical Services. In 1972-3 he spent a sabbatical year as a visiting scientist at University College, Wales with Prof. Sir John Meurig Thomas, former director of the Royal Institution and Chair of Chemistry at Cambridge University.
read morePhilly Materials Day 2023
Philly Materials Day, a day-long science and engineering festival, returned to an in-person program this year on Saturday, February 11, 2023. More than 85 volunteers from 15 different LRSM-affiliated research groups combined forces with Drexel’s Materials Science and Engineering department to run a series of hands-on demonstrations for more than 600 attendees (K-12 students and their families).
read moreCharles J. McMahon, Professor Emeritus, MSE
Charles J. McMahon, Professor Emeritus in the Department of Materials Science and Engineering, passed away on December 10, 2022, at the age of 89. Dr. McMahon earned a bachelor’s degree in Metallurgical Engineering in 1955 from the University of Pennsylvania and returned in 1963 for a postdoctoral fellowship in the newly formed Department of Metallurgy and Materials Science (now the Department of Materials Science and Engineering). He joined the faculty of that department, where he remained throughout his career. In addition, he was a member of the LRSM community and a valued participant in ARPA- and NSF-MRL block grants.
read moreThe Inaugural Diversity Equity Engagement at Penn in STEM Weekend Event
Dr. Ashley Wallace, the LRSM Assistant Director of Education and Outreach, coordinated the inaugural Diversity Equity Engagement at Penn in STEM (DEEPenn STEM) weekend that took place in person October 7-9, 2022. In an effort to address low representation of certain groups in science, technology, engineering and mathematics (STEM), DEEPenn STEM provided prospective graduate students from historically marginalized and traditionally underrepresented backgrounds with the resources to be successful in graduate school and related endeavors. Aiming to diversify graduate-level programs and the global workforce through methodical recruitment and retention efforts, DEEPenn STEM was created to serve as an integral part of the STEM pathway for students to pursue summer research experiences (ex: REUs) at Penn and successfully transition into graduate school and/or STEM careers.
news releaseThe Return of Science Cafés
After a 2 1/2 year hiatus, the LRSM restarted its Science Café’s in Wilmington Delaware, with a presentation by Ottman Tertuliano on August 23rd. “Breaking Bones at the Nanoscale to Heal Them,” was quite a relatable topic with the, predominantly, older audience who were all too familiar with bone issues and repair. Ottman entertained, and enlightened those in attendance for 40 minutes, followed by questions from the captivated audience.
The LRSM Science Café’s began back in 2010, in collaboration with the PBS Nova series “Making Stuff” and had been going strong until February of 2020, when it, like many other in-person events, was paused during the pandemic. Many of the talks have been captured over the years and can be streamed from our video archives page, including this month’s talk.
web pageA Half Century of Research and Educational Outreach
The 48th meeting of the North American Thermal Analysis Society (NATAS) Conference met at Case Western Reserve University August 1-5, 2022. A special session was held entitled the “Andrew McGhie Honorary” organized by Janis Matisons from Intertape Polymer Group. McGhie has been a longstanding leader in NATAS, and his contributions to thermal analysis was rewarded by the Mettler Award in Thermal Analysis in 2011. In 1992, McGhie was also awarded the NATAS Outstanding Service Award and became a NATAS Fellow in 1989. He is also a Past President of NATAS (2007).
Collaboration Helps Decode the Structural Signals of Flow in Disordered Materials
If you squeeze very gently, no toothpaste comes out of the tube. Increase the force a bit and the toothpaste suddenly begins to flow. This transition from “no-flow” to “flow” is called yielding, and it is a ubiquitous feature of disordered materials (e.g., dense particle suspensions, foams & emulsions, and metallic glasses). A study led by Larry Galloway, a graduate student in Paulo Arratia’s lab, and Max (X.) Ma, a MRSEC alum from Arjun Yodh’s lab, provides new insights on how the evolution of the material micro-structure, quantified using the concept of excess entropy, can be used to predict this yielding transition in disordered materials. To do so, the team employed novel experimental methods (Galloway, Keim, Ma, Arratia, Jerolmack, and Yodh), numerical simulations (Teich, Graham, Kammer, Arratia, Jerolmack), and theory (Galloway, Celia Reina). The team found that the quantity excess entropy can be used to characterize the sample microstructure, as well as to develop a phenomenological model that captures flow quite well in both experiments and simulations in cyclically sheared dense colloidal systems. In particular, the team finds that the inception of flow (i.e., yielding) is marked by the material loss of memory.
news releaseYang Group Develops Inflatable Photonic Displays
Se-Um Kim, a postdoctoral researcher in Shu Yang’s lab, together with fellow postdocs, Young-Joo Lee and Dae Seok Kim, and graduate students Jiaqi Liu and Haihuan Wang, have developed a new photonic display platform via pneumatic inflation of thin membranes made from the main-chain chiral nematic liquid crystalline elastomers (MCLCEs), where the liquid crystal mesogens are arranged in a helix. By taking advantage of the large elasticity anisotropy and large Poisson’s ratio (> 0.5), the researchers geometrically program the size and the layout of the encapsulated air channels to achieve broadband color shift from near-infrared to ultraviolet wavelengths with less than 20 % strain perpendicular to the helical axis of MCLCEs. Each channel could be individually addressed as a color “pixel” to match with surroundings or to display 7-segment digits. It overcomes physical constraints in traditional photonic crystals made from isotropic materials. The large degree-of-freedom in the layout of the pixels and the air channels, together with unique mechanochromic performance of MCLCEs offers new insights to create new biomimetic, highly responsive and complex photonic devices with relatively simple operations.
read articleThe Perpetual Fragility of Creeping Hillslopes
Pour a pile of sand onto a table. It will avalanche until the slope relaxes to the angle of repose, where friction prevents gravity from pulling grains downward. All experience tells us that the pile should then just sit there. By probing a seemingly static sandpile with a highly sensitive optical interference technique, however, our experiments have revealed a seething and ceaseless creeping motion. The dynamics of the sandpile are remarkably similar to a cooling glass, suggesting that mechanical disturbances in granular systems play a role akin to thermal fluctuations in glasses. This similarity can be harnessed to change the softness (or strength) of the sand pile by applying different disturbances. This work explains how ubiquitous granular materials such as soil move below their angle of repose, and how distinct perturbations may excite the catastrophic loss of strength that is associated with failure such as landslides. Our findings contribute to emerging evidence of deep connections in the mechanical behavior of disordered materials across scales, as part of IRG1.
press releaseLRSM Awarded New PREM Grant
A Partnership for Research & Education in Materials (PREM) between the University of Puerto Rico (UPR) (Humacao and Cayey undergraduate campuses) and the University of Pennsylvania (PENN) Materials Research Science & Engineering Center (MRSEC) will sustain a long-term and successful collaboration between UPR and PENN that began in 1998. The program will advance scientific discovery and technical development by widening and diversifying the amount of current and potential participants doing high-quality research. It strengthens research thanks to an active year-around collaboration between researchers at the two Hispanic-serving institutions and PENN on subjects as the study of novel carbon-based materials with interesting electrical properties and the modification of surfaces of common materials that can be used as sensors and purification devices. This rich research environment serves as the base for expanding and developing a pipeline model that has proven to be successful in increasing the mentioned underrepresented group in research careers. The model focuses on the recruitment, retention, and graduation of undergraduate Hispanics, women, and Afro-Latin students from disadvantaged backgrounds (low income, first-generation in college) into materials research. It begins as early as PreK-12 with outreach activities to make youth aware of exciting and rewarding research careers in materials, and then doing actual research during their college studies starting at freshman and sophomore levels.
news releaseCongratulations to the 2021 MRS Fellows!
Please join us in congratulating Professors Eric Stach and Shu Yang on being selected as Fellows of the Materials Research Society. MRS Fellows are recognized for “sustained and distinguished contributions to the advancement of materials research”.
Eric Stach was recognized “For the innovative development and application of in situ and operando methods for the characterization of nanoscale phenomena in materials, largely through transmission electron microscopy”.
Shu Yang was recognized “For outstanding contributions to the design, synthesis, assembly, and fabrication of responsive, foldable, and buildable soft and bioinspired materials, and for pioneering research on mechanical instabilities and photonic structures.”
You can read more about this award through the link below.
news releaseMark Licurse, Engages Students via Remote Learning and Tabletop SEM
This past fall, 2020, LRSM’s Director of Education and Outreach, Dr. Mark Licurse, and Prof. David Pope, Department of Materials Science and Engineering, developed a new online-only class “Failure Analysis of Engineering Materials.” The class was featured by Penn Engineering Today in an article by Melissa Pappas. The spin was that it was originally planned to be even more hands-on than other classes, focused on real-world problems and failures, but the pandemic forced them to start from scratch to ensure students could engage virtually. “We had designed this course to be very hands-on and expose students to real-world situations where materials fail, break or collapse, having potentially devastating consequences,” says Licurse. “We would ask students to act like detectives to figure out how and why a material had failed, showing the applicable significance of materials science and mechanical engineering.”
Luckily, they were able to take many illustrative images using a new tabletop Scanning Electron Microscope, purchased with help of the Penn MRSEC. The resulting class was well-received with high levels of student engagement. Clearly the pandemic is changing all aspects of life, but from here the question will be how will this class’ success shape future versions of the class? This remains unknown, but lessons learned will immediately be applied to the LRSM’s Summer Course in Materials Science for High School Students (the Penn Summer Science Initiative).
read articleArjun Yodh Receives Michael S. Feld Biophotonics Award
Please join us in congratulating Prof. Arjun Yodh, on being selected as the 2021 recipient of The Optical Society of America (OSA) Michael S. Feld Biophotonics Award. Arjun is being honored specifically for pioneering research on optical sensing in scattering media, especially diffuse optical and correlation spectroscopy and tomography, and for advancing the field of biophotonics through mentorship.
The Michael S. Feld Biophotonics Award honors Prof. Michael Feld for his fundamental contributions to applications of photonics technologies to solving biomedical problems. Established in 2012, the Feld Biophotonics Award recognizes individuals for their innovative and influential contributions to the field of biophotonics, regardless of their career stage. The scope of the award encompasses all areas of biophotonics ranging from fundamental optics discoveries in biology to development of new theoretical frameworks and novel instrumentation to clinical translational research for biomedicine.
You can read more about this award through the link below.
Congratulations, Arjun on this well-deserved recognition.
news releaseLRSM Serves Philadelphia Area High School Students in Penn No-cost Virtual Summer Program
In July 2020, the LRSM contributed to the inaugural University of Pennsylvania Rising Scholar Success Academy (PennRSSA), a free-of-cost four-week summer program for rising seniors in the Philadelphia area. The entirely virtual program was a collaborative effort between the Provost’s Division of Student Engagement and 8 Schools of the university. The program consisted of both live and asynchronous learning with the purpose of immersing “… rising seniors in an academic, career, and post-secondary preparatory experience.” The LRSM provided content to 807 rising seniors (57.89% women, 41% underrepresented minority) from 82 different high schools in the area as part of the PennRSSA “Academy” portion of the program. Various materials science concepts were covered in the form of pre-recorded videos by Schuyler Patton, a local high school teacher, as well as supplemental readings, learning checks, and unit tests. The schedule also included two days of live engagement with the students, where Dr. Wallace facilitated an icebreaker and Q&A segment while Schuyler led the live demonstrations (i.e. Introduction to Materials & Cooking with Materials). Learn more about RSSA here.
news releaseAgarwal Group Creates Helical Topological Exciton-Polaritons, a New Type of Quasiparticle
A study from MRSEC seed led by Ritesh Agarwal published in Science, reports a new type of quasiparticle, helical topological exciton-polaritons in a system of monolayer of tungsten sulfide strongly coupled to a photonic crystal. Exciton-polaritons, which are half-light half-matter quasiparticles inherit useful properties of their constituents but typically suffer from scattering losses. By creating a new type of topological insulator for polaritons, the Agarwal group demonstrated propagation of polaritons around sharp bends with no backscattering losses. In addition, due to spin-momentum locking, the polaritons with opposite spins (helicities) were transported to different directions. These studies were performed at relatively higher temperatures (200K) and without the need for strong magnetic fields, which make them promising for fundamental studies and device applications. Topological helical polaritons provide a new platform for developing robust and tunable polaritonic spintronic devices for classical and quantum information processing applications.
news releaseProfessor E. Ward Plummer, 1940-2020
Sadly, our friend, and former director of the LRSM, E. Ward Plummer, died suddenly and peacefully on July 23 in Baton Rouge, LA. Ward was a major player within the LRSM for many years. During his time at Penn, Ward led various interdisciplinary materials “Thrusts” (now called IRGs), and he was Director of the LRSM from 1990 to 1993. After leaving Penn, Ward served for many years on the LRSM external advisory board, until his death.
read moreArratia, Yodh groups collaborate to elucidate connections between structure, relaxation, and applied stress during plastic deformation.
A study conducted by graduate student Larry Galloway, post-doc Xiaoguang Ma, and faculty members Paulo Arratia, Douglas Jerolmack, and Arjun Yodh, provides new insights about how the microscopic structure (characterized by excess entropy) of disordered solids is related to the external stresses applied and to the resulting shifting motions of individual constituent particles during plastic deformation. The team conducted experiments on a two-dimensional colloidal solid sheared by the motion of small magnetic needle. The shearing force caused the solid to plastically deform, and concurrent video microscopy enabled tracking of the movements 50,000 particles in the solid.
Galloway, K.L., Ma, X., Keim, N.C., Jerolmack, D.J., Yodh, A.G., and Arratia, P.E., Scaling of relaxation and excess entropy in plastically deformed amorphous solids. Proceedings of the National Academy of Sciences, online published May 19, 2020 https://doi.org/10.1073/pnas.2000698117.
news releaseSynthetic Nanovesicles Coated with Oligomannose Can Help Understanding Glycans on Coronavirus
A study from MERSEC Seed lead by Percec laboratory recently published in PNAS, reported a methodology to create cell-like nanovesicles coated with linear and branched oligomannose, which is widely presented on the surface of bacterias and viruses including coronavirus. Both linear and branched oligosaccharides synthesized by automated glycan assembly (AGA), with hydrophobic N-pentyl linkers, have been used to create Janus glycodendrimers via a new isothiocyanate–amine coupling reaction. These nanovesicles exhibiting lamellar surface morphologies, which mimic the recognition structures of cell-surface glycans (sugars) and viral glycoproteins. This methodology is likely to be useful in helping elucidate mechanisms of significance for translational medicine such as the camouflage functionality employed by viruses to evade recognition. This collaborative work was carried out by the labs of Percec from Penn Chemistry, Seeberger from Max Planck Institute of Colloids and Interfaces, Golm, Germany, Klein from Temple University, and Moeller from RWTH Aachen University.
news releaseThe LRSM Building Recreated in 'Minecraft'
This image of the LRSM was built by Ben Hammel and Randy Chen (screenshot by Makarios Chung) for Penn “Minecraft.” A group of Penn students set up a Minecraft server and coordinated recreating the campus together over the last two weeks of March. Junior Andrew Guo first came up with the idea for a virtual Penn campus inspired by news of a Japanese elementary school graduation on “Minecraft.” The Penn students also interacted with other students at Columbia University and Brown University who were working on similar projects to set up possible Hunger Games-like challenges between schools.
read moreEric Stach, New LRSM Director
Eric Stach will be our new LRSM Director starting July 2020! Eric joined the Penn faculty in 2017 and is currently Professor of Materials Science and Engineering and Faculty Chair of the Nanoscale Characterization Facility in the Singh Center for Nanotechnology. In addition to academics, Eric has led efforts and centers at Lawrence Berkeley National Laboratory and Brookhaven National Laboratory, as well as in industry at Hummingbird Scientific which he co-founded. Eric takes over the reins from Arjun Yodh, who has directed the LRSM and its NSF-MRSEC since 2009.
press releaseRecent Journal Covers Highlight MRSEC Activity
LRSM research is often made visible by cover images on technical journals. This slideshow highlights recent covers from research in the LRSM community. The research leading to these cover images are all based on MRSEC support, including direct support and MRSEC support for Shared Experimental Facilities.
more information10th Annual Philly Materials Science and Engineering Day
Saturday, February 1st, 2020 saw the 10th annual Philly Materials Science and Engineering Day, a day-long festival hosted by Drexel University Materials Science department and the Penn MRSEC. This event has been held annually since 2011 with an average annual attendance of 900+ people. This year, volunteers taught Materials Science concepts to elementary and middle school-aged students and their families with hands on demonstrations and workshops. For example, MEAM professor, Jordan Raney, demonstrated the utility of instability while PhD candidate Daniel Rosen, from Chris Murray’s MSE lab, illustrated the super-elastic phenomena of shape-memory alloy using a coil of NiTinol. Nearly half of the Philly Materials Day demo tables were staffed by 70+ graduate students, undergraduate students, and faculty from 15 LRSM-affiliated groups.
more informationReconfigurable Nematic Liquid Crystal Drops
A study from MRSEC IRG-3, recently published in Nature, reports on reversible shape transitions of spherical drops containing liquid crystals into a rich variety of non-spherical drop morphologies with unique internal structure. The collaborative work was carried out by graduate students Wei-shao Wei and Sophie Ettinger and PhD alum Yu Xia, in the labs of Arjun Yodh and Shu Yang. The unexpected discovery provides new understanding about how molecular polydispersity—a condition where the lengths of liquid crystal molecules vary widely—can drive simple droplets to change into unusual shapes. Observations and modelling reveal that chain length polydispersity plays a crucial role in driving these morphogenic phenomena, via spatial segregation. This insight suggests new routes for encoding network structure and function in soft materials.
news releaseCompression Leads to Stiffening in Tissues But Not Biopolymer Gels
Even though the cells in soft tissue contain network of filamentous polymers and are imbedded within extracellular matrices made from chemically distinct but physically similar polymers, they respond differently to compression and stretch compared to the polymer networks alone. Work by two groups within the MRSEC reveal that this difference arises when volume conserving cells are placed in a filamentous network and constrain the way these networks can reorient when the system is deformed. This work,led by Paul Janmey, Professor in the Perelman School of Medicine’s Department of Physiology and in Penn Engineering’s Department of Bioengineering, and Vivek Shenoy, Eduardo D. Glandt President’s Distinguished Professor in Penn Engineering’s Department of Materials Science, resulted from extensive use of instrumentation in the viscoelastic characterization lab in the LRSM and on experimental and theoretical work supported by the MRSEC.
press releaseLRSM Team Creates and Understands Novel Chiral Microparticles
Helen Ansell, Dae Seok Kim, Eleni Katifori, and Randall Kamien are part of a team that studied the spontaneous formation of chiral microparticles with submicron features. The surface structure is stabilized by liquid crystalline order in the initial spherical droplets. Using a combination of analytic and computational techniques, the team established that the patterns on the surface corresponded to loxodromes — paths of constant angle with respect to the lines of longitude. The work, published in Physical Review Letters, is the latest in a string of interdisciplinary success by the IRG on Pluperfect materials. The LRSM has had a long history of mixing chemistry, materials, and physics and continues to do so.
news releaseAn Authentic Research Experience for Undergraduates
Angelica Padilla recently participated in the LRSM’s NSF-supported Research Experience for Undergraduates (REU) program. The program dates back to 1988 and has seen almost 700 participants. The 10 week summer program immerses students in hands-on research, supervised by a faculty member associated with the LRSM. Each student works on independent research projects and adopts similar roles as graduate students, thereby giving them an authentic research experience. Angelica, a senior chemical and biomolecular engineering student at Penn, worked in Paulo Arratia’s Complex Fluids lab where she studied active fluids. Here, she shares her experience.
news releaseJ. Robert Schrieffer: The LRSM’s first Nobel Laureate
John Robert ‘Bob’ Schrieffer died on July 27, 2019 in Tallahassee, Fl., at the age of 88. Bob was the first of five Nobel Prize winners working at the LRSM when, in 1972, along with John Bardeen and Leon Cooper, he won it for their Theory of Superconductivity, conventionally known as the BCS Theory. Bob said that he had the breakthrough idea (as a graduate student) on the New York Subway while attending a conference in early 1957 — strokes of genius can occur anywhere at any time. Born in Oak Park, IL, Bob studied electrical engineering at M.I.T. for two years before switching to Physics and graduating in 1953. He completed his Ph.D. at U. Illinois with John Bardeen in 1957. He spent almost 20 years as a distinguished member of the Physics Department at the University of Pennsylvania, 1962-80; during this entire period he was a key member in defining the activities of the LRSM and its ARPA- and NSF-funded materials center. Among other contributions, he helped develop the Su-Schrieffer-Heeger model for polyacetylene, including its topological solitons, and he also did important work on surface science and chemisorption before leaving Penn to become Director of the Theoretical Physics Institute at UC, Santa Barbara. In 1992, Bob moved to the National High Magnetic Field Laboratory at Florida State University in Tallahassee, where he was the lab’s chief scientist. He received other honors, such as the National Medal of Science in 1983, and he served as president of the American Physical Society in 1996.
news releaseGene Mele Elected to the National Academy of Sciences
Congratulations to our friend and colleague Eugene J. (Gene) Mele, Christopher H. Browne Professor of Physics and Astronomy, who has just been elected a member of the National Academy of Sciences (2019). Gene is best known for his work, with Charles Kane, on topological insulators. Additionally however, for almost 40 years, Gene has been a key contributor to the LRSM community, especially to our NSF MRL and MRSEC centers. Amidst this “other” important research are extensive theoretical contributions to LRSM efforts on carbon nanotubes and buckyballs, graphene, and many aspects of surface science. Gene was also awarded the Breakthrough Prize in Fundamental Physics (2019), the Franklin Medal (2015), and the Europhysics Prize for CMP (2010).
news releaseRobert Maddin: A Founding Father of the LRSM
Robert Maddin, one of the four founders of the LRSM, died on March 3, 2019 at age 100. Bob was born in Hartford CT in 1918. He graduated from Yale with a doctorate in engineering in 1948, and he joined the Metallurgy department at Penn in 1955, just after it formed, as Professor of Metallurgy and Director of the School of Metallurgical Engineering, a position he held until 1972. In January, 1973 he was appointed University Professor, a position he held until his retirement in 1983. Along with Eli Burstein, Robert Hughes, and Norman Hixson, he was responsible for the creation of the LRSM in 1960. He was a member of the LRSM Executive committee and was well known for his work on mechanical properties, phase transitions, and defects in metal single crystals, alloys, and metallic glasses. He was also department chair of Materials Science and Engineering (formerly Metallurgy) from 1972-83. In 1983 he joined Harvard as a professor of Anthropology, worked on ancient metallurgy, and was also a curator in the Peabody Museum. The LRSM will continued to honor and remember him, as it has for many years, through sponsorship of the Maddin Lectures which bring prominent materials researchers to Penn.
relatedChristopher B. Murray Elected to the N.A.E.
We congratulate Christopher Murray, Richard Perry University Professor and Professor in the Departments of both Materials Science and Engineering, and Chemistry as a Penn Integrates Knowledge faculty member. Chris has just been elected to the National Academy of Engineering (NAE) “for invention and development of solvothermal synthesis of monodisperse nanocrystal quantum dots for displays, photovoltaics, and memory.” Chris is an intellectual leader in the MRSEC, especially as a core contributor to both of our nanocrystal IRGs during the last two funding cycles (links below). Chris has also been a strong participant in our education and outreach efforts, including the PREM program with the University of Puerto Rico. His scientific contributions include (but are not limited to) the development of nanocrystalline materials broadly defined, for example the creation of “artificial atoms” — nanocrystals or quantum dots — that self-assemble into devices with completely new multi-functionalities.
IRG3: Pluperfect Nanocrystal Architectures
IRG4: Controlled Function in Inter-dimensional Materials (2011-17)
Former LRSM Director, Donald N. Langenberg, Passes, January 25, 2019
Donald Newton Langenberg (image taken at the LRSM 50th Anniversary Symposium, 2012)
The LRSM recently lost an old friend and former Director, Don Langenberg, who passed away on January 25, 2019 at age 86. Don joined the Physics department at Penn in 1960, where he specialized in low temperature solid state physics, specifically focusing on electronic band structure in metals and semiconductors. He later carried out classic experiments on quantum phase coherence and non-equilibrium effects in superconductors for which he became a world authority. In 1972 he became director of the LRSM. This was an important time, in part because the source of LRSM funding was changing from ARPA to NSF. Don led the effort to garner our first major center funding from the NSF, through the so-called Materials Research Lab (MRL) program. The LRSM Director position, which he carried out with aplomb, was his first foray into administration and represented the beginning of a highly successful transition to administration (broadly defined). In 1974 he was appointed vice-provost for graduate studies and research at Penn and from 1974-77 was member of the Advisory Committee on Research of the NSF. From 1975-80 he was a Trustee of Associated Universities before becoming Acting Director of the NSF, 1980, and Deputy Director 1980-82. In 1983 he became Chancellor of the University of Illinois, Chicago, 1983-1990, and then Chancellor of the University of Maryland System, 1990-2002, after which he became Chancellor Emeritus on his retirement.
Among Don’s other achievements: he was a Trustee of Penn ,1990-2000, President, American Association for the Advancement of Science,1991, Chair, Board of Directors, National Association of State Universities and Land-Grant Colleges, 1991, and President of the American Physical Society, 1993. Other awards he has received include the John Price Wetherill Medal of the Franklin Institute and the Distinguished Contribution to Research Administration Award of the Society of Research Administrators, in addition to honorary degrees from several universities.
more informationMele & Kane Winners of the 2019 Breakthrough Prize
Physicists Eugene Mele and Charles Kane of the School of Arts and Sciences are being recognized for their innovative work on topological insulators. Kane and Mele have been named winners of the 2019 Breakthrough Prize in Fundamental Physics and will share the $3 million award “for new ideas about topology and symmetry in physics, leading to the prediction of a new class of materials that conduct electricity only on their surface.”
Kane, the Christopher H. Browne Distinguished Professor of Physics, and Mele, also Christopher H. Browne Distinguished Professor of Physics, both in the Department of Physics and Astronomy, have long collaborated, sharing ideas and predictions in their field of condensed matter physics. Their theoretical contributions introduced a new class of materials known as topological insulators. These materials have the unique characteristic of being electrical insulators on their interior, but have surfaces that are unavoidably conducting.
more: Penn Today news item on Kane & Mele accepting their award.
related: BBVA Foundation Frontiers of Knowledge Award
State-of-the-Art X-ray Scattering Instrument
In the Spring of 2018, a a brand new instrument for measurements, funded by an NSF-MRI grant with matching support from LRSM and SEAS (and additional building renovations funded by SAS, SEAS, and the Provost) was installed in the LRSM.
The DEXS instrument (“Dual Source and Environmental X-ray Scattering”) incorporates a Xeuss 2.0 small-angle system with Cu and Mo X-ray sources and adjustable sample-detector distances from 7 cm to 6.3 m. This provides scientists with an unprecedent capability to measure structures of materials from the subnanometer to the micron scale on the same instrument. Once the sample is placed in the instrument, all aspects of the measurement are computer-controlled, including collimation and choice of source. The DEXS instrument is also equipped with a wide variety of sample environments and special configurations, including controlled temperature, humidity, grazing incidence, and measurements under tension.
The instrument was commissioned and tested during the summer of 2018, and is now being used by research groups in Materials Science, Physics, and Chemistry, as well as outside academic and industrial users. Anticipated applications of the research being conducted using this instrument include nanoporous metals for energy storage, nanocrystals for light harvesting, polycarbonates in ionic liquids with tunable chemical reactivity, and a variety of others.
$500K Award for New SUPERSeed
The NSF awarded the Penn MRSEC funding ($500K) for a brand new SUPERSeed, entitled Membraneless Organelles with Designed Function from Engineered Assemblies of Intrinsically Disordered Proteins. The objective of the SuperSeed is to construct genetically-encoded materials that predictively self-assemble into micron-size liquid condensates in vitro, and in cells via coacervation of intrinsically disordered proteins (IDPs). The SuperSeed is led by Matthew Good (Cell and Developmental Biology, Bioengineering) and Elizabeth Rhoades, (Chemistry). They will be collaborating with Daniel Hammer and Daeyeon Lee (Chemical and Biomolecular Engineering) and Jittain Mittal (Lehigh University). The proposed studies leverage team expertise on intrinsically disordered proteins and principles of molecular self-assembly to construct mesoscale structures inside living cells. By integrating computational design and experimentation this team will develop rules that govern the assembly of nanoscale IDPs into organelles. Additionally, synthetic organelles will be engineered to sense the environment and regulate cellular decision-making, thereby mimicking and extending the rules of life that underlie cellular organization. This Penn collaboration was among the winners of highly competitive summer SuperSeed competition spanning all MRSECs (34 submissions).
Charles Kane and Andrew Rappe Identify New Insulating Material
Charles Kane and Andrew Rappe were part of a team that identified a new class of insulating material that has a conducting surface. The surface is stabilized by a pattern of symmetry similar to the pattern on an ordinary piece of wallpaper. Using a combination of analytical and computational techniques, the team predicted that Sr2Pb3 is a topological Dirac insulator and computed the special features of its surface states. The work, published in Science, is the latest in a string of interdisciplinary successes by this integrated Topological Science Seed project team of the MRSEC. The LRSM has supported the seed, with the goals of establishing new principles in the burgeoning field of topological physics, and translating these principles to real materials.
news releaseMAXS Facility helps pave the way for safer smaller batteries and fuel cells
A recent study, published in the journal Nature Materials, suggests a new and versatile kind of solid polymer electrolyte (SPE) that already has twice the proton conductivity of the current state-of-the-art material. It was led by Karen I. Winey, TowerBrook Foundation Faculty Fellow, professor and chair of the Department of Materials Science and Engineering, and co-supervisor of the LRSM’s Multiple Angle X-ray Scattering (MAXS) facility.
This publication is the result of 10+ years of structural characterization of precise polyethylenes made possible by the MAXS facility. MAXS was designed to incorporate a broad angular range to capture structural features from 0.26 to 80 nm, which is particularly important for acid- and ion-containing polymer that self-assemble into hierarchical structures.
news releaseJason Burdick Named the Robert D. Bent Professor of Bioengineering
Congratulations to Jason Burdick who has been named the Robert D. Bent Professor of Bioengineering. Jason participates in our MRSEC grant as a member of the Interdisciplinary Research Group (IRG) on Structural Chemo-Mechanics of Fibrous Networks in which he works on strain reinforcing fibrillar materials. Jason has been a Bioengineering faculty member since 2005.
read articleVivek Shenoy Named the Eduardo D. Glandt President's Distinguished Professor in SEAS
Congratulations to Vivek Shenoy, who has been named the Eduardo D. Glandt President’s Distinguished Professor in SEAS. Vivek is co-leader of our Interdisciplinary Research Group (IRG) on Structural Chemo-Mechanics of Fibrous Networks. He is a theorist who studies mechanisms of plastic deformation in collagen networks, among other materials. Vivek has been a faculty member in the Department of Materials Science and Engineering since 2012. He also serves as the director of the NSF Science and Technology Center for Engineering Mechanobiology.
read articleShu Yang, with IRG3, are Making Atomic Thin Nanosheets Stand Up for Better Energy Storage
In a paper published in Nature, faculty from IRG3: Pluperfect Nanocrystal Architectures reports a fundamentally new and scalable approach to prepare electrodes from atomic thin 2D nanosheets in the vertical orientation via self-assembly. The method beautifully marries soft matter assembly and functional hard nanomaterials by creating a coherent and long-range ordered liquid crystal phase of 2D sheets of titanium carbide, Ti3C2, a member of the MXene family. The resulting electrode films show rapid ion diffusion in thick films, exhibiting unprecedented energy storage performance, retaining almost 100 % of the capacitance after 20,000 cycles of galvanostatic cycling at a rate of 20 A/g, and nearly thickness-independent (up to 200 micrometers, or 0.2 mm), a thicknesses equal to or exceeding that of commercial electrodes.
press releasePhiladelphia Science Festival 2018
LRSM graduate students, post-docs, and faculty hosted interactive exhibits at the Philadelphia Science Festival’s Science Carnival, on the Benjamin Franklin Parkway on Saturday, April 28, 2018. This free, final event of the festival, engaged people of all ages about fields of science. This year, the LRSM sponsored two interactive exhibits at the Science Carnival: “How does levitation work?” run by the Yodh soft matter group, and “Can you move a train with magnets?” run by the Jariwala group from electrical engineering (see full list of volunteers below). The LRSM has participated in the Science Festival since 2011, its inaugural year. Literally tens of thousands of interested people attended the all-day Carnival.
“Can you move a train with magnets?”
Ravindra Saxena (Masters student, Nanotechnology)
Stefano Roccasecca (Undergraduate student, Physics)
Akshaya Venkatakrishnan (Masters student, Nanotechnology)
Deep Jariwala (Professor, ESE)
“How does levitation work?”
Sophie Ettinger (PhD student, Physics)
Analisa Hill (PhD student, Physics)
Chandan Kumar Mishra (Post doc, Physics)
Alexis de la Cotte (Post doc, Physics)
Xiaoguang Ma (Post doc, Physics)
Arjun Yodh (Professor, Physics)
8th annual Philly Materials Science and Engineering Day
Saturday, February 3rd, 2018 saw the 8th annual Philly Materials Science and Engineering Day, a day-long festival hosted by Drexel University Materials Science department and the Penn MRSEC. This event has been held annually since 2011 with an average annual attendance of approximately 1,000 people. This year, volunteers taught Materials Science concepts to elementary and middle school-aged students and their families with hands on demonstrations and workshops. For example, MSE professor Eric Stach performed feats of levitation using high temperature superconductor materials while PhD candidate Lisa Mariani, from Kevin Turner’s MEAM lab, explored soft materials’ properties using everyday materials like strips of scotch tape. Nearly half of the Philly Materials Day demo tables were staffed by 65 graduate students, undergraduate students, and faculty from 12 LRSM-affiliated groups.
Other demonstrations included:
- Magic Liquid Crystal: Is it a liquid or a crystal? (Shu Yang, MSE)
- Tribology: principles of friction, wear and lubrication (Robert Carpick, MSE)
- Chemical tools for tackling neurodegenerative disease (E. James Petersson, Chemistry)
- Shrinky Dink Polymers (Karen Winey, MSE)
- Bouncy Balls & Borax: Polymerizing Glue (Eric Schelter, Chemistry)
- Diving Into Different Dimensions (Marija Drndic, Physics)
- The surprising behavior of soft matter (Arjun Yodh, Physics)
- Muggle Magic (Fakhraai, Chemistry)
- Light and Color: From Molecules to LCD Screens (Lee Bassett, ESE)
- Non-Newtonian Fluids (Steve Szewczyk, MSE)
Read the Penn Current Article
more informationIRG-1 Team Identifies Failure Signatures in Disordered Solids
In a paper published in Science, a team of faculty from IRG-1 (Rearrangements and Softness in Disordered Solids) identified fundamental new connections between microscopic structure and dynamic rearrangements in glassy materials. In this truly interdisciplinary and multi-scale work, the team tested new ideas about “softness” in 15 different experiments and simulations spanning materials whose constituent size spans 7 orders of magnitude, and whose mechanical stiffness spans 13 orders of magnitude.
read articlePrincipal of Condensed Matter: In Honor of Tom Lubensky
A special symposium, entitled ‘Principal of Condensed Matter: In Honor of Tom Lubensky’, took place at the LRSM November 3 and 4, 2017. Tom is a long-time and current member of the LRSM-MRSEC, and he is one of Penn’s leading theoretical physicists. He was awarded the APS Buckley Prize and is a member of the National Academy of Sciences, in part for his foundational contributions to soft condensed matter physics. The symposium featured lectures from fifteen of this field’s elite from all over the world leading off with a Quasi-crystal talk by Paul Steinhardt (Princeton), a former Penn faculty and LRSM member, and ending with an exciting talk about characterizing disorder by Paul Chaikin (NYU), a former graduate student, post-doc, and professor at Penn. In between were more speakers including Tom’s son, David, who presented new research in biophysics. The symposium drew well over 100 scientists including many former students, post-docs, collaborators, and friends. The symposium dinner was held at The Study in University City on Saturday evening. Details of the event can be found at http://www.lrsm.upenn.edu/event/tomfest/
news releaseCelebrating the Life and Contributions of an LRSM Founding Father
Approximately 75 colleagues gathered for an all-day memorial to celebrate the life and contributions of LRSM Founding Father, Elias (Eli) Burstein, who, along with Bob Maddin, Robert Hughes, and Norm Hixson, was the driving force in establishing the first academic, interdisciplinary materials lab in the USA in 1960 at Penn, and since then, the LRSM has garnered continuous center funding through 2023. The symposium event was held Friday, October 6, 2017, and featured stories about Eli’s life and scientific achievements from his students and post-docs, faculty colleagues, current and former LRSM directors, and family friends. The event concluded with a dinner in the Singh Center for Nanotechnology attended by Eli’s wife, Rena, and family. Eli was a man of great stature in the physics community, both at Penn and throughout the world. He died in his 100th year on June 17, 2017.
more informationLRSM Awarded 2017-23 NSF Materials Research Science & Engineering Center (MRSEC)
The Laboratory for Research on the Structure of Matter (LRSM) has been awarded a six-year, $22.6 million center grant from the National Science Foundation to support LRSM’s work in cutting-edge materials. The new MRSEC, one of eight selected nationwide, provides crucial support for LRSM’s education and outreach missions, its shared experimental facilities, and the research of three new interdisciplinary research groups (IRGs).
more informationLisa Tran Takes Fifth Place in the Nikon Small World Competition
This video is of cholesteric liquid crystal double emulsions, with water in the inner and outer phases, and cholesteric liquid crystal in the middle phase. The inner water phase has excess salt, which causes the emulsion to swell over time, thinning out the liquid crystal shell. Surfactant is added into the outer water phase, and as the surfactant absorbs onto the liquid crystal-water interface, the cholesteric responds to the surfactant by forming stripes on its surface. The stripes continue to evolve as the shell thins due to the emulsion swelling.
more informationCollaboration demonstrates a new amorphous packing of organic molecules
Stable glasses, disordered solids, are prepared by depositing molecules from a vapor phase onto a cold substrate. Stable glasses are typically birefringent, meaning that the index of refraction of light is different in the directions parallel and normal to the substrate. In most systems this is a result of molecules aligning in a particular direction as they condensate from the vapor phase into a deep glassy state. As such, if a molecule is spherically shaped, one would not expect to observe birefringence.
In a new study, Penn researchers Zahra Fakhraai, Patrick Walsh, James Kikkawa, and Joseph Subotnik designed a spherically shaped molecule and demonstrated that despite its round shape, the molecule can produce birefringent glasses upon vapor deposition. Through a series of experiments, graduate students Tianyi Liu and Annemarie Exarhos demonstrated that the birefringence in this system is due to the layer by layer nature of the deposition that allows molecules to pack more tightly in the direction normal to the surface during the vapor deposition. The denser the glass, the higher the value of birefringence. This process can be controlled by changing the substrate temperature that controls the degree of densification. This novel amorphous packing provides an opportunity to reveal fundamental properties of glasses at low energy states, a long standing question in solid state physics. This study was funded by National Science Foundation grants DMR-11-20901, DMR-1206270, CHE-1152488 and DMREF-1628407.
news releaseLRSM Science Camp Expands Opportunities for Philadelphia Middle Schoolers
Since 2011, 7th grade students from Girard College, a boarding school for low-income students from single-parent homes, have spent a week at the LRSM learning about science, technology, engineering, and materials. This summer, for the first time, students from the Pennsylvania School for the Deaf joined the camp. In addition to science and college exposure, this new partnership created novel opportunities for students from both schools to form friendships across lines of difference.
news releaseAlison Sweeney Identifies How Squid Have Evolved to See in Dim Ocean Water
Alison Sweeney, Paul Heiney, postdoc Jing Cai and graduate students James Townsend and Tom Dodson of the School of Arts & Sciences have provided a detailed look into how self-assembled lenses allow squid to see in the dim waters of the ocean. This may one day allow researchers to understand the fundamental principles of self-assembly and to engineer better nanomaterials.
press releaseUltra-Small-Angle to Wide-Angle Dual Source X-ray Scattering Instrument for SEF
The X-ray scattering shared experimental facility (SEF) within the LRSM is about to undergo a dramatic transformation via purchase of a Xeuss 2.0 from Xenocs. Briefly, the new instrument provides structural information at both high and low spatial resolution across a wide range of length scales (0.09 to 600 nm) and thus facilitates study of hierarchical structures in a wide range of hard and soft materials. Further, by incorporating dual sources (Cu and Mo), two solid-state detectors, a stage for grazing incidence, and various sample environments for in situ and operando studies, we anticipate that the impact of this new instrumentation on local materials research and education will be immense. The instrument will advance research on the synthesis, fabrication, processing, and assembly of a wide range of materials systems, and will provide crucial insight about structure relevant to their chemical, electrical, magnetic, mechanical, optical, thermal, and transport properties. The facility will also be integrated into courses at Penn, the outreach activities of the LRSM, and workshops and online training materials are planned to promote its broad use by beginners and to fully develop expert-users.
This major investment was made possible by a recent NSF – MRI grant award (PI: Yodh, co-PIs: Detsi, Fakhraai, Heiney and Winey), with matching funds from the LRSM and Penn Engineering. In addition, the detector will be further improved by resources derived from an ARO-DURIP grant (PI: Winey)
more informationPenn Collaboration Produces Surprising Insights Into the White Spots on Butterfly Wings
In Memory of Elias ‘Eli’ Burstein
The LRSM lost one of its most distinguished members, Elias ‘Eli’ Burstein, on Saturday, June 17, 2017. He was 99 years old, only three months short of a century. Eli, Professor of Physics and Astronomy at Penn since 1958, was the grand old man of the Penn materials community. It was he, along with Bob Hughes, Chemistry, Bob Madden, Metallurgy, and Norm Hixson, Associate Dean of Engineering, who founded the LRSM in 1960, as an academically unique, interdisciplinary materials research laboratory. They obtained the first grants for the LRSM from the Department of Defense, and starting in 1972, the materials center has garnered funding support continuously from the National Science Foundation. Eli graduated from Brooklyn College in 1938 and took graduate courses at MIT and Catholic University, but his doctoral studies were interrupted by WWII, although he subsequently obtained four honorary doctorates. He retired in 1988 as Mary Amanda Wood professor of physics and remained active as professor emeritus until he died.
Eli was extremely prolific in a career that spanned seven decades. He did it all. He worked on fundamental studies of infrared photoconductivity in silicon and germanium, and he carried out ground-breaking research on semiconductors, insulators, metals, and two-dimensional electron plasmas in semiconductors. Much of this work improved our understanding of optical properties in the solid state. In his later years at Penn, Eli was known for his work on SERS, Surface-Enhanced Raman Scattering; these SERS ideas continue to influence researchers in present-day metamaterials. Finally, near the end of his career, Eli was deeply engaged in understanding optical properties of fullerenes (buckyballs) and other carbon structures.
Eli trained well over 40 graduate students and post-doctoral fellows, many of whom have had very distinguished careers of their own. He also encouraged dissemination of scientific knowledge by organizing international meetings, conferences, symposia, workshops, and through the literature as Founding Editor of the journal Solid State Communications, being editor-in-chief 1963-1992. Among his many honors, he was elected to the National Academy of Sciences (1979), and he received the John Price Wetherill Medal from the Franklin Institute, the Frank Isakson Prize from the American Physical Society, and a Guggenheim Foundation Fellowship. He was also a Fellow of the American Physical Society, the Optical Society of America, and the American Association for Advancement of Science.
At the LRSM, we have enjoyed his company at our annual “Burstein Lecture,” named in his honor. Eli is survived by his wife of 73 years, Rena, three daughters, Joanna Mitro, Sara Donna, and Mimi Burstein, and grandchildren, Graham and Susanna Mitro. He will be missed.
If you are interested in learning more about Eli’s life, please explore the following links:
https://en.wikipedia.org/wiki/Elias_Burstein#Honors
https://www.nytimes.com/2017/06/25/science/elias-burstein-dies-physicist.html
National Academy of Sciences Biographical Memoir of Elias Burstein
18th Mid-Atlantic Soft Matter (MASM)
LRSM co-sponsored the 18th Mid-Atlantic Soft Matter (MASM) meeting at Penn, May 19, 2017. The meeting hosted local invited speakers from Georgetown University, Lehigh University, the University of Delaware, and the University of Pennsylvania. It also featured more than 60 contributed sound-bite talks largely from students and post-docs in the mid-Atlantic region. Doug Durian and Rob Riggleman organized the workshop.
LRSM Co-founder Dr. Robert E. Hughes Passes at Age 92
Prof. Robert E. (Bob) Hughes, passed away on April 2, 2017, age 92, at his home in Virginia after a long and distinguished career. We knew him best as professor of Chemistry at Penn, from 1953-64 during which time he was instrumental in establishing the LRSM in 1960. Following DARPA’s request for proposals for an interdisciplinary materials research program in 1959, after the Soviet Union’s successful launch of Sputnik, he was appointed to a committee that included Robert Maddin, Metallurgy, Elias Burstein, Physics, and chaired by Norm Hixson, Associate Dean of Engineering, to write the successful grant proposal that funded the LRSM. One of the most controversial decisions to be made was that of naming the lab. Burstein wanted ‘condensed matter physics’ in the title and Maddin wanted ‘structure of materials’ in the title. Bob Hughes solved the problem by giving it the everlasting and somewhat grandiose title, the Laboratory for Research on the ‘Structure’ of ‘Matter’, thus satisfying both. He returned to the LRSM in 2012 to help celebrate the 50th anniversary of the lab and stated that he always loved his time at the University of Pennsylvania. On leaving Penn in 1964, he returned to his alma mater, Cornell, where he was director of their Materials Science Center from 1968 to 1974. Subsequently, he became the Assistant Director of the National Science Foundation (NSF) from 1974 to 1976 and President of Associated Universities Incorporated (AUI), which administered Brookhaven National Laboratory, from 1980 to 1997.
more informationPenn Engineers Report First Colloidal Crystals with Diamond Structure
A long-standing goal in material science is to create a material with a complete photonic bandgap, in which light would propagate in a manner analogous to the flow of electrons in a semiconductor. This requires the creation of a very challenging three-dimensional microstructure: an ordered periodic array of highly refractive sub-micron particles arranged so as to mimic the structure of carbon atoms in a diamond crystal. It has long been an elusive goal to form such structures by self-assembly, for example using the ability of colloidal microspheres to spontaneously form into colloidal crystals. Penn researchers John Crocker and Talid Sinno lead an NSF funded project that forms novel colloidal crystals from polymer microspheres covered in interacting DNA strands, and which draws upon technology originally developed by an earlier MRSEC project. Their graduate student Yifan Wang serendipitously discovered the diamond structure crystals in recent experiments, and the results are published in Nature Communications. While significant challenges remain to turn the discovery into an bandgap material, self-assembling the diamond crystals is a significant breakthrough. The occurrence of the diamond crystals is unexpected theoretically, and forming them in simulation has also proven elusive; the team conjectures that the crystals form via the transformation of another, yet undiscovered parent crystal.
news releasePhilly Materials Science and Engineering Day 2017
This year marked the 7th annual Philly Materials Science and Engineering Day, held on February 4th, 2017. Through a collaboration between the Penn MRSEC and the Penn and Drexel University Materials Science departments, the day-long event promotes materials research to local K-9 students with tabletop demonstrations and workshops. In all more than 20 LRSM-affiliated graduate students & post-docs volunteered at the event, which draws over 1000 attendees each year.
web pageMRSEC SEED Project Builds Simple Microrobots Powered by DNA
An emerging approach to building microrobotic devices is to fabricate thin film devices that then curl and fold themselves into complex three-dimensional and dynamic shapes, termed microorigami. DNA is superior to other materials that use temperature or pH to control such shape actuation; by using different DNA strands many different motions can be controlled independently, enabling sequential folding or complex robotic actuations. MRSEC postdoc Tae Soup Shim created the first microorigami devices formed from and powered by DNA, working in the labs of John Crocker and Daeyeon Lee, with advice from David Chenoweth and So-Jung Park. The work was recently published in Nature Nanotechnology. By combining photolithography and DNA-based assembly techniques, they could create thousands of identical micromachines in water that can change their shape in seconds when commanded by the addition of DNA strands to solution. These machines demonstrated the ability to flip themselves over synchronously in a controlled manner, such that they all faced ‘up’ or ‘down’ on command. Such functionality required two independently controllable types of DNA ‘muscles’, and would would have been difficult or impossible with earlier microorigami materials. The researchers hope to build still more complicated and capable soft microrobots to interface with biological systems.
news release2016 MRSEC Education Directors Meeting
The Penn MRSEC hosted a one-and-a-half-day meeting of 27 MRSEC education directors and their staff from 20 (of 21) NSF-supported MRSECs across the USA. The program was organized by Nevjinder Singhota, Cornell, the organization chair, and was held here at the LRSM on November 3rd & 4th, 2016.
more informationPKU-Penn Joint Symposium on Molecular Science Frontiers
LRSM co-sponsored and helped initiate the first PKU-Penn Joint Symposium on Molecular Science Frontiers. The event took place at Peking University, Beijing China, July 11-13, 2016. The Symposium covered a wide range of topics from chemistry to physics to materials science and biochemical engineering. Besides scholarship, the workshop helped to developed new synergies between Penn and PKU. Eleven faculty with LRSM affiliation spoke at the Symposium.
Dan Beller, Kamien Group Alum, Wins 2016 Glenn Brown Prize
Dan Beller, Physics and Astronomy alum, won the 2016 Glenn Brown prize from the International Liquid Crystal Society
The Honors and Awards Committee of the ILCS selected Dr. Beller for his thesis work:
For his outstanding theoretical work to identify the rich possibilities and outcomes of controlling defects in nematic and smectic liquid crystals under a variety of boundary conditions. The demonstration of the well controlled disclinations and focal conics is expected to open up a novel route for self-assembly in soft-ordered materials.
You can read more about the prize on the ILCS website: http://www.lcinet.kent.edu/ILCS/main/page101/page113/page21/page21.html
more informationSweeney Lab Sheds Light on Squid Invisibility
As reported in National Geographic, Alison Sweeney and post-doc Amanda Holt of Arts & Sciences showed how a transparent squid uses natural fiber optics as camouflage.
read articleFirst Transistors Made Entirely of Nanocrystal ‘Inks’
The transistor is the most fundamental building block of electronics, used to build circuits capable of amplifying electrical signals or switching them between the 0s and 1s at the heart of digital computation. Transistor fabrication is a highly complex process, however, requiring high-temperature, high-vacuum equipment.
Now, University of Pennsylvania engineers Cherie Kagan, the Stephen J. Angello Professor in the School of Engineering and Applied Science, and Ji-Hyuk Choi have shown a new approach for making these devices: sequentially depositing their components in the form of liquid nanocrystal “inks.”
Their new study, published in Science, opens the door for electrical components to be built into flexible or wearable applications, as the lower-temperature process is compatible with a wide array of materials and can be applied to larger areas.
press releaseBehavior of Materials at the Atomic Scale
Dawn Bonnell, vice provost for research and a nanotechnologist, spoke to NBC Learn about how the behavior of materials change as they approach the atomic scale.
more informationD. Lee, K. Stebe and M. Haase Devise Easier Way to Make Bijels
Bijels are bicontinuous networks of interwoven oil and water channels made stable by a percolating film of interfacially jammed colloidal particles. Traditionally fabricated by a delicate batch process via thermally-induced spinodal decomposition, bijels hold tremendous potential as promising platforms for interfacial catalysis and as fascinating vehicles for fundamental studies. A challenge with the traditional bijel formation route is that it is suitable for only few pairs of liquids with carefully tuned nanoparticle wetting properties. Postdoctoral researcher Martin Haase, working jointly with Profs. Daeyeon Lee and Kathleen Stebe, has devised a new approach, based on solvent transfer-induced phase separation (STRIPS). In STRIPS, bijels are formed continuously, from a diverse set of materials, with new degrees of control over the resulting structure. STRIPS exploits ternary liquid systems, comprising oil, water and a solvent, of which there are hundreds of candidate mixtures. If the solvent is removed in the right way, the oil and water phase separate spinodally, and nanoparticles adsorb and stabilize the structures. The nanoparticle wetting can be tuned in situ using surfactants, broadly diversifying the particles used. Solvent gradients can be tuned, for example, in a microfluidics device or via removal from a supported film, allowing bijel structures to be formed continuously, resulting in hierarchically structured particles, fibers or membranes. With this advance, we have taken a giant step toward realizing the promises of these fascinating new materials.
press releaseLRSM & ASEOP Forge Collaboration with the Korea Institute of Science and Technology (KIST)
In an exciting development, we signed a Memo of Understanding to spur increased collaboration between Korea Institute of Science and Technology (KIST), Materials and Life Science Research Division (MLSRD) and two centers of excellence at the University of Pennsylvania. These include the newly launched Center AESOP (Center for Analyzing Evolved Structures as Optimized Products (AESOP): Science and engineering for the human habitat), directed by Shu Yang and Randall Kamien, and the The Laboratory for Research on the Structure of Matter (LRSM), directed by Arjun Yodh. Our aim is to build on existing collaborations and synergies, and to expand them under the auspices of these centers. This was an exciting visit with tremendous promise of more interaction to come.
web pageVirgil Percec Puts a New Twist on Chirality
The building blocks of life, such as amino acids, sugars and DNA, all exhibit the same enantiomeric form. This phenomenon – known as homochirality – enables biological and synthetic macromolecules to achieve highly ordered structures and thus exhibit function. Recent work from the Percec group challenges the notion that homochirality is a prerequisite for the generation of highly ordered supramolecular crystals, by demonstrating that homochiral and racemic building blocks can self-assemble into crystalline arrays of identically high order. Such self-assembly is possible only via a newly elaborated cogwheel mechanism, in which the exterior of the supramolecular column is invariant to the stereochemistry of its building blocks. Alkyl chain ‘teeth’ on the columns’ periphery interlock to form the highly ordered structures. This mechanism is anticipated to provide access to other homochiral crystals with practical applications in photovoltaics and organic electronics.
news releaseArjun Yodh helps explain "Why Light Matters"
On October 27, 2015, Arjun Yodh, the Director of The Laboratory for Research on the Structure of Matter at the University of Pennsylvania, with, William W. Braham, Professor of Architecture at the University of Pennsylvania and Ravi Sheth, Professor in the Department of Physics and Astronomy at the University of Pennsylvania, spoke on “Why Light Matters” at The Franklin Institute. The event was hosted by Derrick Pitts, Chief Astronomer, The Franklin Institute and was presented to a packed audience in the Franklin Theater.
more informationLRSM summer high school science program participant receives MUREP NASA scholarship
Jordan Caraballo Vega, a freshmen at the University of Puerto Rico in Humacao, was chosen as one of ten students across the United States and Puerto Rico to receive the Minority University Research and Education Programs Small Projects scholarship awarded by NASA. The scholarship covers tuition and summer internships in NASA research laboratories up to a maximum of $15,000 annually for two years. Jordan, a PREM undergraduate, attended the Penn Summer Science Initiative program for high school students in 2014 and worked with Penn professor Jorge Santiago to form the idea for this proposed research project.
more informationLRSM research partnership with University of Puerto Rico receives $3M PREM
A partnership between the University of Pennsylvania and the University of Puerto Rico was one of six to receive $3M in funding from the National Science Foundation (NSF). The program, called the Partnership for Research and Education in Materials (PREM), links NSF Materials Research Science and Engineering Centers (MRSECs) with educational institutions that serve mainly minority populations. The five year PREM will sustain an extraordinarily successful collaboration between the LRSM (which hosts Penn’s MRSEC) and three undergraduate campuses from the University of Puerto Rico. The effort began in 1998 under the NSF CIRE program and has continued with PREM support since 2004. The collaboration will focus on diversifying the pipeline of scientists in all age groups based on research in two general materials topics to integrate research and education: nanoscale interactions of macromolecules at soft and hard interfaces and multi-functional nanodevices from optoelectronic materials.
[ Penn news release ]
[ NSF news release ]
NSF Awards $250K for Topological Materials SUPERSeed
The NSF recently awarded funding ($250K) for a new SUPERSeed, Topological Quantum Materials between Two and Three Dimensions. LRSM’s SUPERSeed will combine theory, computation and experiment on topics that lie at the intersection between materials science and topological physics: layered 2D materials, topological semimetals, and ferroelectric (FE) topological insulators. Senior investigators in the SUPERSeed are Charlie Kane, Gene Mele, and Charlie Johnson from the Department of Physics & Astronomy, Andrew Rappe from the Chemistry Department, and Ritesh Agarwal from Materials Science & Engineering; collaborators include Jessica Anna (Chemistry), I-Wei Chen and Peter K. Davies (both MSE), and Chris B. Murray (Chem/MSE). The research builds on the surprising interplay between symmetry and topology in materials electronic structure, motivated by seminal discoveries about topological insulators at Penn. The Penn collaboration was one of three SUPERSeeds selected for support by the NSF this summer, from a highly competitive group of 23 MRSEC proposals.
more informationNSF Supports Helium Conservation in the Property Measurement Facility
The NSF has awarded additional funds to support helium conservation in the Property Measurement Shared Experimental Facility (SEF). The SEF hosts over a dozen low temperature measurement capabilities requiring liquid helium. Using the award, the Property Measurement Facility will add a helium re-liquefier to a cryogenic, superconducting magnet system. The new equipment will nearly eliminate helium consumption in the facility, and will enable high levels of instrument availability for end-users. Helium is a vanishing resource on our planet that plays an important role in scientific discovery. This award will allow us to recapture helium rather than releasing it into our atmosphere and, ultimately, outer space.
web pageFormer LRSM Student Pioneers a Materials Breakthrough after Decades of Research
Krishan L. Luthra has recently been recognized for development of a novel lightweight and strong ceramic that is stable at high temperatures. Luthra was a graduate student with Prof. Wayne Worrell, MSE, and was supported by LRSM’s block NSF grant to study “The Chemical Behavior of Materials at Elevated Temperatures” in the 1970s. After completing his Ph.D., he went to work for GE in 1976 and now, almost 40 years later, has met with outstanding success in developing a new lightweight, strong ceramic that is stable at very high temperatures. It is being used by GE in advanced jet engines that have potential savings of up to 10% in fuel cost while improving engine thrust by 25%. To date this development has helped GE generate more than $100 billion in sales to airlines and has wider applicability.
more informationNew soft matter topical group of the American Physical Society
GSOFT is a new topical group within the American Physical Society is devoted to the science of soft condensed matter. LRSM research in our soft matter IRGs and Seeds are intellectually coupled to this new APS group, led by LRSM faculty member Randall Kamien.
[ APS Topical Group on Soft Matter ]
news releaseCrystal-crystal phase transitions with liquid intermediate states
Single-particle-resolution video microscopy of colloidal films reveal that transitions two different colloidal crystals (square- and triangular-lattices) occur via a two-step nucleation pathway with liquid nuclei in the intermediate stage. The nucleation pathway is favored over the direct one-step nucleation because the energy of the solid/liquid interface is lower than that between solid phases.The findings suggest that an intermediate liquid could exist in the nucleation processes of solid–solid transitions of many metals and alloys, and provide guidance for better control of the kinetics of the transition and for future refinements of solid–solid transition theory.
read articleLRSM Science Café @ World Cafe Live
The LRSM Science Café has formed a new partnership with World Cafe Live (3025 Walnut St., Philadelphia, PA), just off the Penn campus and only two blocks from the LRSM building. Beginning in January, 2013, our Science Cafés will be held in the upstairs room at WCL, starting at 6:30 pm. This is a larger venue than usual and we encourage attendees to come early for dinner before the presentation which will last, typically, 30-45 minutes and be followed by an open discussion session between speaker and the audience. The WCL is readily accessible by train, 30th St. Station, bus, 9, 21 and 42, and car, by on-street Pay and Display parking.
more informationRussell J. Composto receives NSF Special Creativity Award
The award recognizes his pioneering research on the dispersion and assembly of gold nanorods confined to polymer nanolayers and their potential applications for optical property control.
news releaseDennis Discher Elected to National Academy of Engineering
Dennis E. Discher, Robert D. Bent Professor of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia. For elucidation of the effects of mechanical forces on cell physiology and stem cell development.
read moreCharlie Kane, 2012 Oliver E. Buckley Prize
Prof. Charlie Kane will be awarded the 2012 Oliver E. Buckley Prize in Condensed Matter Physics by the American Physical Society. Professor Kane and two other researchers are being recognized “For the prediction and subsequent discovery of the new phase of matter known as topological insulators in two dimensions, also known as quantum spin Hall insulators, which lead to its generalization and prediction in three dimensional system.” The Buckley Prize will be presented at the APS March 2012 meeting in Boston, MA Feb. 27-March 2, 2012 at a special Ceremonial session.
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